Previous EPR and ENDOR studies on Cu(II)-doped single crystals of -glycylglycine have determined the copper binding site as being interstitial to two glycylglycine molecules. One of the molecules coordinates to the metal through both its amino nitrogen and peptide carbonyl oxygen. The similarity in the Cu(II)O=C-NH- molecular fragment of this system with the Cu(II)~~~N=C-NH- fragment in copper coordinated imidazole compounds suggest that the peptide nitrogen of this glycylglycine is amenable to study using ESEEM spectroscopy. Preliminary 3-pulse ESE experiments show modulation frequencies and amplitudes similar to those found from the remote nitrogen coupling in copper - imidazole compounds. A study of this system is important in that it constitutes the first unambiguous ESEEM determination of couplings to a peptide nitrogen in a copper system. Approximate e2qQ/h and parameters for the 14N quadrupole interaction, as determined from preliminary ESEEM results, are 2.6 MHz and 0.6, respectively. These values are significantly different than those found by NMR for the peptide nitrogen in the undoped crystal which suggests that changes occur in nitrogen bonding interactions upon copper coordination.